Hurricane Florence has more than 10 million people in its crosshairs as the monster storm closes in on the US East Coast with uncertainty over its projected path spreading worry across a widening swathe of the country.

Hurricane Florence has more than 10 million people in its crosshairs as the monster storm closes in on the US East Coast with uncertainty over its projected path spreading worry across a widening swathe of the country.

Faced with new forecasts that showed a more southerly threat, Georgia’s governor joined his counterparts in Virginia and North and South Carolina in declaring a state of emergency, and some residents who had thought they were safely out of range boarded up their homes.

The National Hurricane Centre’s best guess was that Florence would blow ashore as early as Friday afternoon around the North Carolina-South Carolina line, then push its rainy way westward with a potential for catastrophic inland flooding.

Florence’s winds in the afternoon were down to 120mph from a high of 140mph, and the Category 4 storm fell to a Category 3, with a further slow weakening expected as the storm nears the coast.

Based on the latest 11 a.m. forecast for the southward track of Hurricane Florence after making landfall and acting on a recommendation from @GeorgiaEMA officials, I have issued an emergency declaration for all 159 counties in Georgia. Read more here: https://t.co/FmO4iELdYq

In contrast to the hurricane centre’s official projection, a highly regarded European model had the storm turning southward off the North Carolina coast and coming ashore near the Georgia-South Carolina line.

Reacting to the possibility of a more southerly track, Georgia governor Nathan Deal declared an emergency but did not immediately order any evacuations.

“I ask all Georgians to join me in praying for the safety of our people and all those in the path of Hurricane Florence,” Mr Deal said.

The shift in the projected track spread concern to areas that once thought they were relatively safe.

In South Carolina, close to the Georgia line, Beaufort County emergency chief Neil Baxley told residents they need to prepare again for the worst just in case.

Waves crash under a pier in Kill Devil Hills, North Carolina (Gerry Broome/AP)

“We’ve had our lessons. Now it might be time for the exam,” he said.

Their entire neighbourhood evacuated in Wilmington, North Carolina, David and Janelle Garrigus planned to ride out Florence at their daughter’s one-bedroom apartment in Charlotte.

Unsure of what they might find when they return home, the couple went shopping for a recreational vehicle.

“We’re just trying to plan for the future here, not having a house for an extended period of time,” David Garrigus said.

A paddle boarder gets in some exercise ahead of the arrival of Hurricane Florence (Mic Smith/AP)

Melody Rawson evacuated her first-floor apartment in Myrtle Beach and arrived at Atlanta Motor Speedway in Hampton, Georgia, to camp for free with three other adults, her disabled son, two dogs and a pet bird.

“We hope to have something left when we get home,” she said.

Forecasters worried the storm’s damage will be all the worse if it lingers on the coast.

The trend is “exceptionally bad news,” said University of Miami hurricane researcher Brian McNoldy, since it “smears a landfall out over hundreds of miles of coastline, most notably the storm surge.”

With South Carolina’s beach towns more in the bull’s-eye because of the shifting forecast, Ohio vacationers Chris and Nicole Roland put off their departure from North Myrtle Beach to get the maximum amount of time on the sand. Most other beachgoers were long gone.

“It’s been really nice,” Nicole Roland said. “Also, a little creepy. You feel like you should have already left.”